Isidore was immediately interested in the Caster once she had noticed the nature of his own cybernetic body, given the nature of it. Given her matter of dress as well as the weapons she was seen wielding last night, Isidore could only assume that this Caster in particular was some sort of inventor, or perhaps even a "fellow" alchemist. If this were the case, then it opened up more potential avenues of where this partnership could lead. It could very well be possible that this Caster may be able to help the alchemist perfect his weapon of choice... or even allow him to accomplish that.
"Yes, locating a discrete location could easily be arranged. I've got a perfect meeting place set up, though I hope you're fine traveling through the Paris Underground. It's a method of travel I've found useful in order to avoid any unwanted encounters... and it seems we may indeed run into one if we continued overland from what I've seen. As for scouting..."
Isidore opened his gym bag, revealing three more of the same type of drone he was utilizing to scout out Caster's workshop. Turning them on and throwing them in the air, Isidore pushed a few buttons on the ocular device attached to the side of his head, allowing them to fly using motorized propellers. He sent each of them to a specific district; one to the Foreign, another to the Latin, and a third to the Canal districts.
"My Servant is not with us at the moment, but hopefully he will rendezvous with us on the way there. I had him scout out specifically for your... other allies. It would be ashamed if they decided to seek us out, after all."
Of course, this was merely a bluff, as Assassin was not too far off.
Stay a good distance near Caster's Master, Assassin. Somewhere close enough to break the distance in case they make any moves on us, but far enough to where they don't suspect a thing. Don't make any sudden moves yet... we still want to at least try to gain their trust.
With all that established, Isidore began to head over to the nearest manhole, beckoning the two ladies to follow suit.